The disclosure relates to an arrangement having devices that permit optical absorption spectroscopy to be carried out.
The absorption spectrum of living tissue, in particular skin, has relatively low light absorption over wide ranges and is therefore generally accessible to spectroscopy with corresponding light wavelengths. One technical difficulty here is the strong scattering of the light in tissue. Depending on the wavelength, the light can travel distances of a few centimeters in the tissue, but covers such distances only via numerous scattering processes. The propagation of light in the tissue corresponds to a diffusion process rather than to the light propagation of straight-line rays. Owing to this uncertainty relating to the optical paths in the tissue, carrying out spectroscopy in the tissue becomes more difficult. The resulting results may be falsified in the process. It might also be the case that weakly absorbing particles (for example molecules, ions, electrons) as analytes in very small concentrations can be quantified with difficulty or hardly at all. Glucose, for example, is such a weakly absorbing molecule.
There is thus a continued need for improved procedures and devices for carrying out optical absorption spectroscopy. It is desirable, for example, to reliably quantify different analytes independently of their absorption strength despite the strong scattering of the light in the tissue.